Boil Kettle temperature probe problem

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

I brewed a Berliner Weiss yesterday because I wanted to try kettle souring. My plan was to make the wort as usual, transfer to the BK, boil for 15 minutes to sanitize the wort, chill, and then hold it at 95' F without recirculating. The goal was to have as little lactobacillus contact the rest of the brewery as possible.

Everything went as planned and I got the wort to 95' F. All valves were off, no pumps were running and the heating element seemed to be acting right. I know you're not supposed to walk away during brew day, but I felt everything was stable and I had to run my son to hockey and picked up dinner, and came back about an hour later.

When I got back the control panel said the BK was at 108'. I expected a degree or two of drift occasionally, but I thought it was strange that it was more than 10' off, so I touched the pot and it was HOT. The kettle thermometer (Blichmann) and my TheraPen confirmed it at 142' F. Shocked

I've noticed in the past that sometimes when I'm heating to boil, the wort will be near boiling (foop forming and steaming) but the PID reads 120 (or some other ridiculously low number). If I tap the temp probe inside the pot with a spoon, the reading will then jump up to 205 or whatever. This doesn't happen all the time, but often enough that I watch for it so I don't accidentally boil over.

I tried the tap this time (Rule #2 - Double Tap - anyone? Wink

), and it did jump to 140 - but only briefly before it quickly dropped back to the low 90's and fired up the element again, even though it was already way too hot. I switched the temperature probe wiring and power to heating element to the HLT plugs on the control panel, and that PID read the same things.

I guess this is a long story asking if my kettle probe is bad. I've never tried to do anything other than boil with it in Manual mode. I had attributed the reading problems during boiling to air bubbles on the probe tip causing inaccurate readings but maybe it has never really been working right?

I've brewed less than 20 batches on this system, so wouldn't think that it has been over used. Anyone else have these problems with the boil probe? Any suggestions other than replacing it?

David_H · Posted: Fri Jan 06, 2017 5:38 pm Post subject:

Mac,
The first thing to check is the cable. I had a similar issue (different symptoms) with a fluctuating temp reading and there was a bad connection in one of my cables. Change cables, and change which PID you plug into, separately of course to see if you can isolate where the problem is. The temperature probe itself is a fairly solid piece of equipment with very little to go wrong, the cable has a bunch of individual solder joins just waiting to go bad.

Good Luck, David

**kal**

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

I should mention that I ended up transferring the wort to HLT, and it's holding temp fine.

Because I was monkeying around with hoses and spoons and thermaPen's and pH meters in the BK at around 100' to 140' F, I decided to ensure an infection free environment and re-boil the wort. Farewell two vials of Lacto - it was probably roasted at 140' anyway.

Luckily I had a third vial that I was going to use to create a kettle sour that I was going to blend into a "sour" imperial pumpkin beer that, well - isn't. It has Brett character, but no tartness. I've since discovered this is likely due to the high hop load and alcohol level - both things that lacto specifically doesn't like. I'll make a sour batch and blend to keep the sour aspect.

I boiled in the HLT, cooled through the CFC while recirculating back into the HLT, purged with CO2 and pitched my final vial of lacto. The clear problem with this set-up is the HLT doesn't read temp unless wort is flowing past the valve, so I now have two hoses, a pump, and my HLT that all have Lacto in it, which is what I was trying to avoid in the first place. I figured it was this scenario though, or I dump the batch. Confused

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

Thanks Kal and David. As I mentioned in the first post 5th paragraph (it wasn't worded well), I disconnected the BK probe wire from the back and plugged in the HLT sensor cable. I then switched the BK heating element cable to the HLT power plug. So I switched everything over to the HLT PID and had the same problem. That's what led me to believe it was the sensor, and not the cable or the PID.

I need to finish cleaning the brewery today (it was a long day yesterday) and test the pH and all. I'll see what I can do with the probe tip, thanks for the suggestion. I'll hook up the BK cable to the HLT too and see if that changes anything, but I suspect it's the probe.

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

Maybe not the best place for this question: After I dip my Hanna pHep pH meter into Lacto slurry, can I StarSan it? Clearly it's designed to test acid levels, but I've only ever rinsed it with RO water.

**kal** · Posted: Fri Jan 06, 2017 6:23 pm Post subject:

**kal** · Posted: Fri Jan 06, 2017 6:25 pm Post subject:

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

**kal**

**kal** · Posted: Fri Jan 06, 2017 6:54 pm Post subject:

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

McGruber · Joined: 12 Aug 2014 Posts: 237 Location: Idaho

**kal** · Posted: Fri Jan 06, 2017 7:10 pm Post subject:

Wow indeed! Love it when companies are responsive like that.

Kal